Reverse-current relay.



PATENTED APR. 1'7, 1906.

E. M. HEWLETT. REVERSE CURRENT RELAY.

APPLICATION FILED OCT. 22, 1904.

2 SHEETS-SHEET l,

Inventor.

Edward M. Hewlett. bymflfig y Witnesses.

PATENTED APR. 17, 1906.

E. M. HEWLETT. REVERSE CURRENT RELAY.

APPLICATION FILED OCT. 22, 1904.

2 SHEETS-SHEET 2 Inventor. Edward M. Hewlett.

Witnesses.

conductors.

UNITED STATES EDWARD M. HEWLETT, OF SGHENEOTADY, NEW YORK, ASSIGNOR TO OFFIOE.

GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

REVERSE-CURRENT RELAY.

To all whom it may concern."

Be it known that I EDWARD M. HEWLETT, a citizen of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in Reverse-Current Relays, of which the following is a specification.

My invention relates to reverse-current relays; and its object is to provide a novel, compact, and efiicient structure for relays of this type.

Reverse-current relays having two movable windings, one energized from the current in the circuit to be protected and the other energized from a circuit in which current does not reverse with a reversal of ourrent-flow in the first circuit, are well known in the art. A common form of relay consists in a small electric motor of the commutator type, the field or the armature being ener gized from the circuit to be protected and the other member of the motor being ener 'zed from a source which does not reverse. hus it may be connected in shunt to the circuitv to be protected or energized from an independ--- ent source, such as a battery or other inde-' pendent circuit.

My invention consists in the novel form of connection between the movable armature and the relay-contacts controlled thereby.

My invention will best be understood by reference to the accompanying drawings, in which-- Figure 1 shows a side elevation of a relay constructed in accordance with my invention, and Fig. 2 shows a front elevation of the same.

In the drawings, A A represent bus-bars, generator-leads, or other conductors to be protected.

B re resents the field structure of the relay, W iich consists simply of a magnetic member supported close to and artially surrounding the conductors A A. his member B is provided with field-poles b b, which are made detachable in order to enable the mem-- ber B to be sli ped into position around the his construction of the fieldmagnet member is similar to that disclosed in a former patent, No. 730,371, issued to me June 9, 1903. Between the field-poles b b is suspended the movable armature C. (Shown in dotted lines in both figures.) This armature Specification of Letters Patent.- I

Application filed October 22,19q4. SarialNo. 229,546. 7

Patented April 17, 1906'.

has a vertical shaft which is supported in bearings in the two protecting-caps D D, which are made of non-magnetic material and which are supported from the field-poles b b and completely inclose and protectthearmature O. The armature is provided with the commutator-brushes O 0, (shown in Fig. 1,) which are provided with terminals 0 v0, supported outside the u per cap D. The lower cap D is provide with a set-screw P, forming a bearing for the lower end of the armature-shaft and affording convenient means for adjusting the position of the armature.

F represents a spiral spring surrounding the lower end of the armature-shaft. and normally holding a pin 9 on the upper end of the armatureshaft in engagement with a stop d on the upper inclosing cap D.

The upper end of the armature-shaft can ries a cam H, on which rides a roller 1, suported from a pivoted lever i, as shown in ig.'2. This lever guides the roller and re celves the lateral pressure due to the inclined surface of the cam. The roller 1 carries a spindle J, the upper-end of which extends into a dashot or other suitable retarding device K. he spindle J carries near its center the bridging member L, which when the spindle J. is raised by the rotation of the armature C and cam H bridges the. contacts M M, which are provided with suitable ter minals m m for connection in the trippingcircuit.

Adjustably secured to the ole-pieces b I) is a magnetic member E, wiiich acts as a magnetic shunt for the armature. This magnetic member is separated from the polepieces by an air-gap or by strips of n' -1nagneticmaterial e, as shown in Fig. By means of the supporting-screws e the'distance between the member E, and pole-pieces b b may be varied so as to vary the effective reluctance of the magnetic shunt. Byjthie means the torque of the armature is readily adjusted. The retarding device K and the stationary contacts M M are supported from the posts N N, which are secured to the pole- 'pieces I) b. With this structure the relay is made compact and self-contained.

The operation of the relay will be evident from the fore oing description. The armature is norma ly held by the spring F in the position shown, with the pin 9 in engagement .so as to cause roller I to raise spindle J to with the stop d. When the fiow of current through the conductors A A is in the normal direct on, the torque of the relay assists the spring tension in holding the armature against t estop. When the current reverses, however the torque of the relay will be reversed in direction and will oppose the spring tension. With a reverse current-flow of a predetermined amount the armature will be rotated away from the stop, rotating cam H,

bring the bridging member L in engagement with the contacts M M and to close the tripping circuit. The amount of reverse current-flow upon which the relay operates may be adjusted not only by varying the tension of spring F, but by adjusting the position of the magnetic shunt E relative to the polepieces 5 b, as has been heretofore explained.

I do not desire to limit myself to the particular construction and arrangement of arts here shown, but aim in the a ended c aims to cover all modifications w ch are Within the scope of my invention.

What I claim as new, and desire to secure by Letters Patent of the United States, is

1. In a relay, a stationar field-magnet .member, an armature journa ed between the poles thereof, a cam carried by the armatureshaft, a reciprocating member adapted to be moved by said cam, and a switch-contact carable spindle supported by said roller, and a switch-contact carried by said spindle.

4. In a relay, a stationary field-ma net member, an armature with a vertical s aft 'ournaled between the poles of the field memer, a cam carried at the upper end of said shaft, a roller bearin on said cam, a vertically-movable s Andie supported by said roller, a pivoted ever guiding said roller and receiving the lateral ressure thereof, and a switch-contact carrie by said spindle.

5. In a relay, a stationar field-magnet member, an armature journa ed between the poles thereof, a cam carried by the armatureshaft, a reciprocating member adapted "to be moved by said cam, a switch contact carried by said reci rocating member, and means for retarding t e movement of said reciprocating member. a

6. In a relay, a stationary field-ma net member, an armature with a vertical s aft j ournaled between the poles ofthe field memher, a cam carried at the upper end of said shaft, a roller bearing on said cam, a verti cally movable spindle supported by said roller, a switch-contact carried by said spindle,*-and means for retarding the movement of'said spindle.

7. In a relay, a stationar field-magnet member, an armature j ourna ed between the po.es thereof, a cam carried by the arn1atureshaft, a reciprocating member adapted to'be moved by said cam, a switch-contact carried by said reciprocating member, and means normally opposing the movement of said armature.

8. In a relay, a stationary field-ma net member, an armature with a vertical si aft j ournaled' between the poles of the field memher, a cam carried at the upper end of said shaft, a roller bearingon said cam, a vertically movable spindle supported by said roller, a switclrcontact carried by said spindle, and means normally opposing the movement of said armature. p 9. In a relay, a stationar field-magnet member, an armature journa ed between the poles thereof, a stop adapted to be engaged by the armature, a spring arranged to hold said armature normally in engagement with said stop, a cam carried by the armatureshaft, a reciprocating memberadapted to be moved by said cam, and a switch-contact carried by said member.

In witness whereof I have hereunto set my hand this 20th day of October, 1904.

EDIVARD M. HEWLETT;

Witnesses:

BENJAMIN B. HULL, HE EN ORFoRn. 

